There are a number of methods and also systems for decomposition of hydrocarbons into a carbon part and hydrogen. The carbon part can thereby be produced in a number of different variants with regard to quality and density. The applicant himself has developed various methods in this connection and reference is made here to, e.g., the applicant's Norwegian patent applications No. 91 4904 and No. 92 1359. These applications concern methods and systems which are intended for continuous production of carbon in the form of carbon black and hydrogen.
From DD 292 920 is known a method for pyrolytic decomposition of hydrocarbons into carbon black and hydrogen with a plasma torch in a reaction chamber. By adjusting the enthalpy value induced into the feed stock in a range between 3 and 8 kWh/kg and the reaction period between 0,1 and 1 sec. one quality of carbon black corresponding to acetylene carbon black is produced.
From DD 211 457 is known a method and an apparatus for the production of carbon black and hydrogen with a plasma torch in a reaction chamber. A part of the hydrogen is recycled and is used as plasma gas. Feed stock in the form of hydrocarbons as liquid or gas is introduced radially via nozzles in one end of the reaction chamber and is mixed into a turbulent flow of plasma gas at a temperature between 3500 K and 4000 K. The reaction chamber is equipped with tempering zones where the reaction products are quenched to a temperature of about 1100 K.
From WO 89/06260 and EP 411 160 are known apparatus for the manufacturing of carbon black by the traditional production method which consists in a combustion of hydrocarbons by the supply of air. The apparatus consist of a combustion chamber, a tapered section and a reaction chamber contiguous to it. The tapered section and the reaction chamber are equipped with supply channels through the walls for introducing the feed stock.
Most of the previously known methods have to be described as discontinuous methods in which the apparatus could only be in operation for short periods of time, or where a further developed product was manufactured from the carbon formed. Alternatively a complete decomposition was not performed, with the result that the end product was not pure carbon together with hydrogen.
The traditional production methods for carbon black in a continuous process have been conducted as a combustion of hydrocarbons by the supply of air. The qualities achieved were dependent on the method in which air or oxygen was supplied, and whether oxygen was used in a surplus or a deficit. The methods were inefficient since substantial parts of the hydrocarbons which were to be converted were used as energy sources for the process, thus obtaining a low utilization factor. In addition the yield was further reduced due to the fact that the combustion process was not complete, thus causing both carbon and nitrogen oxides to be produced. The waste gases from the processes will not be able to be used for any other purpose than as a fuel gas, with the consequent release of polluting environmental gases.